Will Smith thrilled partygoers at Gabrielle Union's birthday on Saturday (27.10.12).when he gave an impromptu rap performance.

The Hollywood hunk was attending the actress' 40th birthday party when he joined Doug E. Fresh to perform both the theme from his former TV show 'Fresh Prince Of Bel Air' and 'Summertime', according to TMZ.

Will's wife Jada Pinkett-Smith - who wed the 'Men In Black' star in 1997 - recently praised Will as the best husband ever and admits she couldn't be happier with her family.

Jada - who has two children, Jaden, 14, and 11-year-old Willow, with Will - said: ''There are no negatives being married to Will Smith! I swear Will has to be one of the most outstanding fathers. Not only just loving him, and him being my husband, but when I look at how he loves his children, I go, 'Thank you! I made such a good choice.' I hit the jackpot with that one.''

Jada also says being married to Will has made her grow as a person as well as understanding the importance of letting him be his own person.

She explained: ''Part of being in a partnership is that you have to support the spirit of it. Being in a partnership like that has forced me to become bigger and to grow, and to allow him to grow and be all that he's meant to be on this planet.''